1. Field of the Invention
The invention relates to a heating chamber, particularly a low-temperature carbonization (LTC) chamber for waste, which is rotatable about its longitudinal axis and has a number of heating tubes located in the interior, each of the heating tubes being secured by one end thereof to a first end plate and by the other end thereof to a second end plate. The invention also relates to a method for replacing the heating tubes located in such a heating chamber.
The heating chamber is used for thermal waste disposal, especially by the low temperature carbonization (LTC) process.
The so-called LTC process has become well known heretofore in the field of waste disposal. This process and a system operating in accordance therewith for thermal waste disposal are described, for example, in the European Patent Publication EP-A-302 310 and and the German Patent Publication DE-A-38 30 153. The system for thermal waste disposal by the LTC process includes, as essential components, an LTC chamber (pyrolysis reactor) and a high-temperature combustion chamber. The LTC chamber converts the waste, which has been supplied thereto via a waste conveyor, into LTC gas and pyrolysis residue. The LTC gas and the pyrolysis residue, after suitable preparation, are then delivered to the burner of the high-temperature combustion chamber wherein a molten slag is produced therefrom. The molten slag is removed via an outlet and, after it has cooled down, appears in vitrified form. Via a flue gas line, flue gas which has been produced in the process is fed to a chimney serving as an outlet. A waste heat steam generator serving as a cooling device, a dust filter system, and a flue gas cleaning system, in particular, are built into this flue gas line.
The LTC chamber (pyrolysis reactor) is usually formed of a relatively long, rotating LTC drum having, in the interior thereof, a number of parallel heating tubes by which the waste is heated, largely with the exclusion of air. The LTC drum rotates about its longitudinal axis. Preferably, the longitudinal axis of the LTC drum is inclined somewhat from the horizontal, so that the LTC material collects at the outlet of the LTC drum and can easily be removed therefrom. As the drum rotates, the waste which has been raised drops onto the heating tubes located therebeneath. Because the waste can include heavy components, such as rocks, bottles, and metal and ceramic parts, a danger exists that the heating tubes may be damaged thereby. Besides this mechanical load or strain, a severe thermal strain of the heating tubes must also be considered. The LTC chamber may have a length of 15 to 30 m, so that it represents a significant capital investment.